Self-cleaning electrical connector



April 6, 1968 R. F. DORRELL 3,378,810

SELF'CLEANING ELECTRICAL CONNECTOR Filed May 15 66 c H/ w &z m m j/ m m I 8 5 L m in $1 Q g: H

, ka g or" f fl zjgogbfie% United States Patent 3,378,810 SELF-CLEANING ELECTRICAL CONNECTOR Robert F. Dorrell, Des Plaines, Ill., assignor to Amphenol Corporation, Broadview, III., a corporation of Delaware Filed May 13, 1966, Ser. No. 549,986 Claims. (Cl. 33995) ABSTRACT OF THE DISCLOSURE An electrical connector wherein at least one contact is mounted in a cavity in a contact body and extends longitudinally therefrom into mating engagement with another contact. Means are provided to urge the contact longitudinally outward from the cavity while causing lateral engagement between the contact and the contact body, and helical guide means are disposed along the cavity and the contact to impart rotative motion to the contact upon relative longitudinal motion between the contact and he conact body thereby resulting in a wiping or cleaning action on the contact surface.

This invention relates to electrical connectors and more particularly to electrical connectors wherein the contacts mate in abutting relationship rather than in a telescoping pin and socket arrangement.

In connectors having abutting type contacts there exists the problem of reliable electrical contact between the mating contacts. Contaminating films build up on the mating portions of the contacts to impair electrical conductivity therebetween. Further, in connectors having an abutting contact relationship, the contacts move relative to each other under mechanical shock or vibration. This motion disturbs the contact point and possibly the contact resistance if reliable electrical contact is not made between the contacts.

It is the principal object of the present invention to provide a connector having contacts which mate in abutting relationship and have reliable electrical contact therebetween.

It is another object of the present invention to provide a connector having a contact which spins upon engagement with a mating contact to effect a wiping motion therebetween.

It is another object of the present invention to provide a connector wherein the contact resistance between mating contacts is not adversely affected by vibration or mechanical shock.

Other objects of the present invention will become more apparent as the detailed description proceeds.

In general the present invention comprises in an electrical connector, a contact body having a cavity extending longitudinally inward from one end thereof. A contact member is movably mounted within the cavity and extends outwardly therefrom. Means are provided for urging said contact member longitudinally outward from said cavity while providing lateral engagement between said contact member and said contact body. Helical guide means are provided disposed along said cavity and said contact member in contact therewith to impart rotative motion to said contact member upon relative longitudinal motion between said contact member and said contact body.

Further understanding of the present invention may best be obtained from the accompanying drawing wherein:

FIGURE 1 is a cross sectional view of a connector showing a contact assembly therein in mated condition and constructed according to the present invention.

FIGURE 2 is a cross section of the connector of FIG- URE 1 showing the contact assembly in an unmated condition.

3,378,810 Patented Apr. 16, 1968 FIGURE 3 is a section of the contact assembly of FIG- URE 1 taken along lines 3-3.

Reference is made to FIGURES 1 and 2 wherein is shown a contact assembly 10 according to the present invention mounted within a dielectric body 12 of a connector. In FIGURE 2 the contact assembly 10 is shown disengaged from its mating contact 14 and in FIGURE 1 in abutting engagement therewith.

The contact assembly 10 comprises a. contact body 16 having a passage 18 formed therein. A helical groove 20 is cut in the walls of the passage 18. A spring 22 is mounted within passage 18 and a ball 24 is disposed on top of the spring 22. A contact 26 having an embossment 28 on the surface thereof is slidably dis-posed within the passage 18 of contact body 16. The embossment 28 of contact 26 is sized to engage and ride within the groove 20 as shown in FIGURE 3. The end 30 of contact body 16 is crimped over so as to restrain escape of the embossment 28 from the helical groove 20 of passage 18. The contact 26 has an inclined rear surface 32 that engages the ball 24. The spring 22 and ball 24 are sized to exert an axial force on the contact 26 forcing it outwardly from the con tact body 16. The inclined surface 32 of contact 26 translates the axial force from the spring 22 into a lateral force wherefrom constant electrical contact is maintained between the contact 26 and the contact body 16.

The contact body 16 has a reduced portion 34 which engages a shoulder portion 36 of dielectric body 12 to restrain axial motion of the contact body 16. Axial motion restriction is further aided by a snap ring 38 disposed about the contact body 16 in a groove 40 cut therein. A soft grommet 42, bonded to the dielectric body 12, effects a waterproof seal about a conductor 44 connected to the contact body 16.

In a disengaged relationship, the contact 26 extends outwardly from the contact body 16 as shown in FIGURE 2. Upon advancement of either contact 26 or contact 14 into mated engagement, the contact 26 will retract within the contact body 16 thereby compressing spring 22. This axial movement of the contact 26 relative to the dielectric body 12 causes rotation of the contact 26 as the embossment 28 rides in the helical groove 20. Thus, mating engagement between contact 26 and contact 14 is effected with a wiping motion by contact 26. This wiping motion destroys any films that exist between the contacts 26 and 14 to provide reliable electrical contact therebetween.

It is to be noted that in FIGURES 1 and 2 the contact 14 is shown as having a concave mating surface 46 with the contact 26 and that the contact 26 has a rounded end portion 48 to further seating with the contact 14. It has been found that this concave seating arrangement is preferred for the practice of the present invention. However, the present invention is not to be limited thereto and may be applied to other abutting contact configurations.

Persons skilled in the art will, of course, readily adapt the teachings of the present invention to embodiments far different than the embodiment illustrated and described above. Accordingly, the scope of protection afforded the present invention should not be limited thereto but should be determined only in accordance with the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows I claim:

1. A contact assembly for an electrical connector comprising a contact body having a cavity extending longitudinally inward from one end thereof, a contact member movably mounted within said cavity and extending outwardly therefrom, means for urging said contact member longitudinally outward from said cavity and into lateral engagement with said contact body, and helical guide means disposed along said cavity and said contact member in contact therewith to impart rotative motion to said contact member upon relative longitudinal motion between said contact member and said contact body.

2. A contact assembly for an electrical connector comprising a contact body having a cavity extending longitudinally inward from one end thereof, said contact body further having a groove helically cut in the interior surface of said cavity, a contact member movably mounted within said cavity and extending outwardly therefrom, means for urging said contact member longitudinally outward from said cavity and into lateral engagement with said contact body, and means connected to said contact member engageable with said helical groove to cause rotation of said contact member upon relative longitudinal motion between said contact member and said contact body.

3. A contact assembly for an electrical connector comprising a contact body having a cavity extending inwardly from one end of said contact body along a portion of the length thereof, said contact body further having a groove helically cut in the interior surface of said cavity along a portion adjacent said end of said contact body, a contact member movably mounted within said cavity and extending outwardly therefrom, an embossrnent on the portion of said contact member within said cavity and sized to engage and ride within said helical groove, and means for urging said contact member longitudinally outward from said cavity and into lateral engagement with said contact body, said embossrnent in said groove effecting rotation of said contact member upon relative longitudinal motion between said contact body and said contact member.

4. In an electrical connector having in line abutting contacts, a contact body, one of said contacts being movably mounted within said contact body and extending outwardly therefrom, said body mounted contact being terminated outside of said contact body in a rounded end portion and within said contact body in an inclinedsurface end portion, the other of said contacts being terminated in a concave end portion to receive the end portion of said body mounted contact in abutting relationship, means for urging said body mounted contact longitudinally outward of said contact body and laterally into engagement with the contact body including a spring means mounted within said contact body and a ball means positioned within said contact body between the spring means and the inclined-surface of the body mounted contact, said contact body having a groove helically cut therein about said contact, and means for engaging said body mounted contact with said helical groove to effect rotation of said body mounted contact upon relative longitudinal motion between said body mounted contact and said contact body.

5. In an electrical connector having in line abutting contacts, a contact body, one of said contacts being movably mounted within said body and extending outwardly therefrom, said body mounted contact being terminated without said contact body in a rounded end portion and within said contact body in an inclined-surface end portion, the other of said contacts being terminated in a concave mating end portion, said contact body having a groove helically cut therein about said contact, an embossrnent on the portion of said contact mounted within said contact body and sized to engage and ride within said helical groove and means for urging said body mounted contact longitudinally outward of said contact body and laterally into engagement with the contact body including a spring mounted within the contact body and a spherical ball positioned within the contact body between the spring and the inclined-surface end of the body mounted contact which urges the contact into lateral engagement with the contact body, said embossrnent in said groove efiecting rotation of said body mounted contact upon relative longitudinal motion between said contact body and said body mounted contact.

References Cited UNITED STATES PATENTS 1,349,405 8/1920 Brown 339-48 1,390,607 9/1921 Farmer 339-48 1,392,558 10/1921 Darrah et al. 339-48 1,973,234 9/1934 Tsavaris 339-8 2,545,939 3/1951 Breitenstein a- 339-8 2,724,096 11/1955 Klostermann 339-255 2,742,626 4/1956 Collins et al. 339-176 FOREIGN PATENTS 200,206 4/ 1958 Germany.

MARVIN A. CHAMPION, Primary Examiner.

JOSEPH H. MCGLYNN, Assistant Examiner. 

